Need suggestions on preamp

I’ve got Hifiman Arya Stealths so have an idea of the level of detail you’re looking for, and I was able to get there with my big rig so it’s definitely doable and highly doubt the preamp is the limiting factor here. I think the amp and possibly the speakers are the source of the problem as the Parasound, although a good amp, is reputed to be on the warm side. I had this Bryston pre paired with a similar McCormack amp to the one below and would highly recommend them given what you’re looking for.

https://www.usaudiomart.com/details/650097052-bryston-bp-6-preamp-with-oem-remote-in-like-new-condition/

https://www.usaudiomart.com/details/650135552-mccormack-smc-audio-ultra-15-dna-1-power-amplifier-upgraded/

Pair them with speakers like these Monitor Audio Silvers (or maybe monitors since you have a small room) and you’ll likely get all the detail you’re missing along with excellent imaging/3D soundstage. Just some ideas FWIW, and best of luck in getting what you’re looking for.

https://www.usaudiomart.com/details/649989850-monitor-audio-silver-300-6g/

My suggestion is the Pass Korg B1 Pre Amp.

Buying one built by a competent EE, will be the best advised as the approach to a purchase. There are also models now having undergone tweaks to the Circuit and VC. I am familiar with the differing builds that can be produced and am always impressed. This option will keep you well under budget. 

@soix - yes people who have heard the Hifiman headphones (really any variant) Arya, Susvara, SE or HE1000 will know what I’m talking about. Wide soundstage with lots of resolving micro detail. Monitor Audio is supposed to be brighter so would make sense that they would resolve better. I probably got the wrong speakers so have to decide if I just want these for their great midrange. I love the LS3/A variants like the Graham Chartwells as well as Falcon Gold Badges, Harbeths, etc. so maybe that’s where I’ll settle and realize the limitations (or looked at different the strengths) of my current setup. 

I don’t disagree with @soix that your speakers may be part of the problem. I’ve listened to the LRS and didn’t find it as resolving as say an ATC-19 or an Aerial Acoustics 5T, both in the $4k range new so you’d be looking at used. They are both stand mount or bookshelf speakers suited to an apartment. But I do think the preamp is also part of the problem. 

In the 1980’s when I was getting into high end audio I swapped preamps looking for a good sounding preamp. After half a dozen failed attempts I bought my first (used) Audio Research preamp. My swapping immediately ended. I had that preamp for fifteen years. A few years later adding an Audio Research phonostage. I have researched and upgraded my system many times and piece by piece ended up with more Audio Research components. Once, I put one in, it stays, except to upgrade to a higher tier.

Audio Research from the beginning has focused on natural musical sound with detail… hence the words high definition written on their components. But unlike many brands that have lost the music in pursuit of detail and slam ARC has carefully walked down the knife edge, not losing the musical core while increasing resolution and black backgrounds. They are built like tanks with intended lifetimes in the decades.

All of my main system is now Audio Research. Highly recommended.

Do not waste your time on ASR. The site focuses on graphs and chart of parameters that obfuscate what components actually sound like to the human ear. The site will point you in the wrong direction if you want high quality sound.

Look at used Audio Research LS or REF series preamps, as contemporary as you can afford. You can see my systems under my User ID.